A nutrient essential to the growth of organisms, and is commonly the limiting factor in the primary productivity of surface water bodies. Total phosphorus includes the amount of phosphorus in solution (reactive) and in particle form. Agricultural drainage, wastewater, and certain industrial discharges are typical sources of phosphorus, and can contribute to the eutrophication of surface water bodies. Measured in milligrams per liter (mg/L). See Also Phosphate

Phosphorus is a nutrient that can encourage the growth of nuisance aquatic plants. These plants can choke up waterways and out-compete native species. High levels of phosphorus in water can be a result of either waste water or, more often, runoff from agricultural land. Ideally, total phosphorus levels in water should be less than 0.04 grams per cubic metre to prevent excessive growth of nuisance plants. Environment Waikato considers that rivers and streams with total phosphorus levels above 0.04 grams per cubic metre are undesirably nutrient-enriched. Three-quarters of all measurements from the New Zealand national rivers programme have phosphorus levels below this value.